Thread cutter and clamping mechanism for looms



April 30, 1968 N. w. BRIDGHAM 3,330,483

THREAD CUTTER AND CLAMPING MECHANISM FOR LOOMS Filed June 16, 1966 2Sheets-Sheet 1 IN VENTOR NOYES W.BR|DGHF\M 2mm W ATTORNEY P 1968 N. w.BRIDGHAM 3,380,483

THREAD CUTTER AND CLAMPING MECHANISM FOR LOOMS Filed June 16. 1966 2Sheets-Sheet 2 IN VENTQR. NOYES W. BRIDGHAM BYQMOW ATTORNEY UnitedStates Patent 3,380,483 THREAD CUTTER AND CLAMPING MECHANISM FOR LOOMSNoyes W. Bridgham, Meudon, Mass., assignor, by mesne assignments, toJohn Donald Marshall and Horace L.

Bomar, trustees Filed June 16, 1966, Ser. No. 557,957 3 Claims. (Cl.139263) ABSTRACT OF THE DISCLOSURE An adjusting means for the cuttingand clamping members of a thread cutter in a bobbin-change loom withwhich independent adjustments may be made to the cutting and clampingedges. The possibility of overadjusting to an excessive pressure iseliminated by using an internally threaded pivot stud having flat-sidedflange members separating its pivotal surface.

This invention pertains to automatic filling replenishing looms and moreparticularly to cutting and clamping means for effectively controllingthe outgoing filling, or that end of filling which extends between theselvage and the nearly exhausted bobbin prior to transfer.

It is a general object of the invention to provide improvements in theloom thread cutter of the type described, thereby rendering increasedefiiciency to that device and simplification to the proper setting ofparts.

It is a more specific object of the invention to provide adjusting meansfor the cutting and clamping members which may be controlled to exertsufficient but not excessive opposing pressure.

It is a further object of the invention to provide an additionaladjusting means for a thread cutter to compensate for tolerance stack upin manufacture or normal wear of parts.

These and other objects of the invention will become apparent as furtherdetails are disclosed.

Thread cutters of the Stafford type which both cut and hold the fillingare often applied to fly-shuttle looms for use at the time of bobbintransfer. As is well known, these cutters are moved into position toaccept the filling yarn between opened jaws, which then perform asevering action, releasing that end which extends to the depleted bobbinand retaining hold of the end extending from the selvage. It is highlyimportant to proper loom operation that the cutter perform a decisiveaction and that the clamping member retain its grip upon the yarn untila subsequent cycle is commenced.

These devices have in the past performed most satisfactorily providedthe individual parts were correctly set and those settings weremaintained. Difficulty was occasionally experienced in the setting ofboth new and worn parts. Where new parts were combined in which thecomponents might have had their allowable tolerances stacked in onedirection, the total overall dimension would have been excessive.Adjustment in this case became difiicult and overadjusting by tighteningof the connecting bolt would likely occur. With malfunction due to wornparts, there is often the tendency for a loom fixer to merely tightenthe bolt upon which the movable blade pivots in an attempt to correctthe 'fault. This will often result in overadjusting to a point where theparts will wear excessively or be broken.

The instant invention discloses simple but effective means for settingand locking the parts in a proper relationship and overcomes thetendency to overadjust. The invention will be described by reference toa specific embodiment thereof as illustrated in the accompanying figuresof drawing wherein:

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FIG. 1 is a perspective view of an assembled thread cutter and bracketwith a portion shown in section; and

FIG. 2 is an exploded view of the parts shown in FIG. 1.

Now referring to the drawings, a bracket 10 has a slide arm 11 by whichthe mechanism is moved in a well known manner and a carrying arm 12. Astationary cutter blade 13 is snugly carried by arm 12 in a slot 14 andfixedly secured by a screw 15 threaded through a hole 16 in the blade13. An angular hole 17 through the blade 13 is adapted to receive one oftwo flat sided ends 18 and '19 of a stud generally designated 20. Theintermediate portion 21 of the stud 20 is circular for pivotallysupporting a movable blade broadly indicated 22. The functioning end ofthe blade 13 has a sharpened edge 23 and a shoulder 24 which willposition the yarn to be cut (not shown).

A stationary clamping blade 25 is held generally parallel with the blade13 by the flat sided end 19 being inserted into an angular hole 26. Ashoulder 27 coacts with the shoulder 24 in maintaining the yarn properlyfor cutting and clamping.

The movable blade 22 is pivotally supported upon the circular portion 21by the stud 20 being inserted through a hole 28 shaped for that purpose.A clamping member 29 which may be of a fiber or laminated plastic typeof material is secured to the movable blade 22 by a screw 30. Pivotalmovement is furnished to the blade 22 by various camming arrangements(not shown) which are well known in the weaving art, any of which mightfunction upon the cam follower end 31 to cause a scissors-like actionbetween the blades above mentioned.

The movable blade 22 has a sharpened edge 32 which will contact with theedge 23 to effect a cutting action. A rounded edge 33 of the clampingmember 29 will coact with a smooth rounded edge 34 of the clamping blade25 to squeeze and hold the yarn therebetween While the scissors-likeends are closed.

Leaf springs 35 and 36 are applied outwardly of the stationary blades 13and 25 with the bent spring ends 37 and 38, respectively, exertingpressure to constantly urge the edges 23 and 34 toward each other. Theassembly is drawn snugly together by a bolt 39 threaded through the stud20 and the nut 40 (FIG. 2). It will be seen that by taking up the bolt39 within the stud 20, the blade 22 will be drawn into closer contactwith the cutter blade 13. By tightening the nut 40, the clamping blade25 may be adjusted toward the movable blade 22. These adjustments maybe, and often are, made in an excessive manner to a point where theclamping member 29 may be damaged or the movable blade may bind.

To overcome the tendency to overadjust the blades, a set screw 41 isthreaded into the arm 12 (FIG. 2) to bind downwardly upon the upper edge42 of the clamping blade 25. By pressing the edges 23 and 34 toward eachother and then tightening the set screw 41, the stationary blades 13 and25 may be locked into a fixed position. When adjustment is made bytightening the bolt 39 and nut 40, the blades are drawn together at thepivot point of the stud 20 and will be held in generally parallelrelationship. This may not act to correct the need for a slightangularity between the cutter and clamping edges. As the parts wear itis possible to loosen the set screw 41 and pivot the clamping blade 25through a slight horizontal :arc to a position nearer the sharpened edge23. If the set screw 41 is then tightened down, the stationary blades 13and 25 will stand apart in an angular relationship.

While one embodiment of the invention has been disclosed, it is to beunderstood that the inventive concept may be carried out in :a number ofways. This invention is, therefore, not to he limited to the precisedetails described, but is intended to embrace all variations andmodifications thereof falling within the spirit of the invention and thescope of the claims.

I claim:

1. In a Stafford type thread cutter for looms, a slide bracket, cutterand clamping means carried by said bracket, said cutter and clampingmeans comprising stationary cutting and clamping blades fixed to saidbracket, a movable blade pivotally supported for scissors-like movementbetween said stationary blades, resilient means for urging said cuttingblade and said clamping blade into engagement with said movable blade,means for drawing said stationary blades, said movable blade and saidresilient means into close mutual proximity whereby said stationaryblades stand apart by a distance of separation, said drawing meansincluding a stud having an intermediate surface for pivotally supportingsaid movable blade and flanged ends separated by said intermediatesurface, and means for locking said stationary blades to control saiddistance of separation.

2. Mechanism as defined in claim 1 wherein said lock- 20 ing meansincludes a set screw carried by said bracket for ch-angeably maintainingthe lateral position of said clamping blade relative to said cuttingblade.

3. Mechanism as defined in claim 2 wherein said stud has an internalthreaded surface the full length of an opening extending therethroughfor adjustably receiving a tightening screw therein.

References Cited UNITED STATES PATENTS 2,515,045 7/1950 Kielczewski eta1. 139267 2,676,620 4/1954 Urquhart 139-263 2,684,085 7/1954 Harris etal. 139-263 X 2,720,225 10/1955 Moon 139263 3,112,774 12/1963 Bostic139-263 2,711,193 6/1955 Consoletti 139263 3,200,851 8/1965 Cadorette139-263 MERVIN STEIN, Primary Examiner.

ROBERT R. MACKEY, Examiner.

J. KEE CHI, Assistant Examiner.

